1. Field of the Invention
This invention relates generally to the art of regulating the flow of high pressure liquids or gasses and, more particularly, to an improved flow restrictor, such as a valve, for conducting a pressurized fluid relatively noiselessly and without detrimental fluid cavitation due to normal orificial throttling through a substantial pressure drop.
2. Prior Art
A wide variety of fluid sound suppressors have heretofore been devised. In one approach, there are devices involving the use of a stack of solid discs, adjacent abutting pairs of which define tortuous, sometimes chambered passages formed therebetween and extending between inlet and outlet edges. Self U.S. Pat. No. 3,514,074 and Scull U.S. Pat. No. 3,856,049 typify this approach.
In another approach, sets of perforated discs are disposed between solid discs, the resulting stack defining tortuous individual passages edgewise through the stack by means of the overlapping relationship of the disc perforations. Such devices are shown in Self U.S. Pat. No. 3,512,864, Orme U.S. Pat. No. 3,899,001, Kluczynski U.S. Pat. No. 3,941,350 and Vick U.S. Pat. No. 3,978,891.
There are also flow restrictors in which long lengths of woven screen material, or ribbons of perforated sheets, are wound into coils on a supporting surface to usually define radial flow through the pores of successive layers of the coiled material. Variations of this approach are shown in Souriau U.S. Pat. No. 3,574,310, Parola U.S. Pat. No. 3,722,854 and White U.S. Pat. No. 3,802,537.
These prior art devices are relatively expensive or difficult to manufacture, or both. In the case of the disc stacks, the discs typically are custom made by expensive processes, are not uniform in surface configuration or geometry, and must be carefully assembled in precise order with particular care to circularly orient one disc relative to another to define the individual passageways therethrough. In the case of the coiled types, it is particularly cumbersome to wind the material into coil form with any kind of precision as to the integrity of the faying contact of successive layers and of the extent of overlap of perforations to attain a desired porosity or distribution of porosity radially through the coil.